Engraving machine



April 25, 1933. J. D. LINN 1,905,725

ENGRAVING MACHINE Filed March 10. 1931 3 Sheets-Sheet l April 25, 1933. .1. D. LINN 1,905,725

ENGRAVING MACHINE Filed March 10, 1931 3 Sheets-Sheet 2 Patented Apr. 25, 1933 UNITED STATES PATENT mm JoHn were? LQINN, or YORK, ENGLAND, ASSIG-NOE crown-HALF ro COOKIE, 'rnonen- 1 TON & SIMMS LIMITED, or roan, ENGLAND, A narrrsn co vrra w EN GRAVIN' G MACHINE 4 u I Application filed March 10, 1931, Serial No. 521,458, and in Great seam May '12, 1930,

j The present invention relates to machines for engraving either raised or sunk letters, figures or designs or for copying the outline of a pattern or article in metal, wood, ebonite or other suitable material, of the type in which a controlling member guided in a desired path serves to determine the movement of-a cutting tool by means of a autograph or like device, the main object o the invention being to enable a series of engraving operations to be carried out automati cally.

2 According to the invention, motion of the controlling member is determined in one direction by a copy cam surface and in a direction at right angles thereto by a groove or its-equivalent, in or on the cam surface, the path of which groove or the like may lie to one side or the other of a mean line, pro

du'cing corresponding motion of the cutting tool to one side or the other of a mean position.

"Inorder that the invention may be clearly understood and readily carried into effect three forms of machine in accordance therewith will now be described with reference to the accompanying drawings wherein -Figures 1 and 2 are respectively a plan and elevation of a machine for engraving a series of characters in a fixed sequence,

Figure 3 is a developed view of a copy cam for use in the machine depicted in Figures 1 and 2,

Figure 4 shows a section of a copy cam and a representation r of a numeral which would be produced in accordance therewith,

Figures 5 and 6 are respectively an elevation and end view of a machine employing a number of copy cams, and

Figures 7 and 8 are respectively an elevation and a section on the line XX of Figure 7 of a machine similar to that shown in Figures 5 and 6, but provided with selecting mechanism whereby characters represented by the copy cams may be reproducedin a predetermined sequence, regardless of their;

order of assembly in'the machine.

In all the forms of the invention illustrat ed the engraving tool is'a rotating tool 1, Figures land 2, driven by means of a pulley 2 in any manner common in engravingma chines and mounted on pantograph 3, the" gu ding member of which is constituted by a pointer 4 or by a roller or equivalent de-' vice adapted to cooperate with one onmore copy cams 5.- The rotating tool '1 is supported by a vertical bearing contained'with in a boss 6 carried by one of the members of the pantograph; A helical spring within. the boss serves to raise thetool 1 out-of contact with the workpiece 7 which is 'supported on a table 8, but the tool is broughtinto contact with the work-piece by the pressure, 1' g '6 T} on a'co-operating member 9, ofa lever 10 pivoted at 11 and operated in a manner hereinafter described.

each character bein g reprodu'ced once only,

the copy cam conveniently'takes the form of a helix and in order to operate in the. desired manneris mounted on" a stationary screwed spindle 12. The main driving shaft 13 is rotated continuously in any suitable manner and 'isprovided with'a'pinion 14- adapted to engage a gear wheel 15 attached 1,

to the copy cam 5, the pinion being of such' alength that the engagement is maintained in all operative positions'o'f thecopycam on the stationary spindle 12. The copycam helix is of theflsame pitch as that of -the screwed spindle 12, thus producing, on rota-1 tion of the cam, suchaxial movement that,'

were'the pointer 4 held stationary, the mean generating line of the helix would' occupy a constant position" relatively .to it: the helix is, however, non-circular in cross-section so as .toconstitutea canrsurfa'ce. In thisihelical cam surface there is cut a groove 16 into which the pointer 4 projects, being maintained in contact with the groove by a s ring 17. In accordance with the various c aracters to be produced, the groove 16 deviates to one side or the other of the mean helical line of the copy cam, thus producing a corresponding motion of the pointer tin a direction parallel to the axis of the cam, motion toward or away from that axis resulting from the cam formation of the surface of the helix. Thus movement in two directions at right angles may be imparted to the pointer 4 resulting of course in a corresponding displacement of the cutting tool 1 whereby the'desired character or design is reproduced on the work-piece 7.

The machine is so designed that engraving of each character is accomplished during a single revolution of the copy cam, but the actual engraving operation takes place dur ing only three-quarters of such revolution,

' the remaining period during which the cam is turning through 90 being referred to as the idle period. It will be seen, therefore, that while the tool 1 must be in contact with thework-piece 7 during the operative period, it is necessary that it should be lifted therefrom during the idle period, and, further, that during the latterperiod the work-piece shall be moved so that the portion of it whereon it'is desired that the succeeding character shall beengraved is brought under the cutting tool. To efl'ect these operations a gear wheel 18 is driven from the shaft 13 by a second pinion 19, the gear ratios being such that the rate of revolution of the wheel 18 is the same as that of the cam 5. Fitted on the spindle 20 which supports the wheel 18 is a cam 21 having a cam groove 22 adapted to engage the lever 10 which, as indicated at 23, is forked to embrace the cam 21'and engagethe groove 22. As seen in Figure 2, this groove is so shaped that over 270 of its rotation it will lift that end of the lever 10 with which it engages and therefore depress the cutting tool 1, while during the remaining 90 the end of the lever 10 engaging the cam groove 22 is depressed so permitting the spring within the boss 6 to raise thetool 1 clear of the workpiece 7. In the form of the invention illustrated it has been assumed that, as indicated in Figurel, it is desired to engrave the reoulred. characters. around a circle and for this purpose the table 8 is mounted in a vertical bearing 24 and provided with a wormwheel' 25"adapted to be rotated by a worm 26. This worm is driven through a universal jointed spindle 27 having a bevel pinion 28 adapted toengage a rack 29 on the gear wheel 18, the said rack extending over not more than 90, so that the pinion 28 and its associated parts are only operated during the idle period thus effecting the necessary transfer of the work-piece during that period.

The development appearing in Figure 3 is that of a helical copy cam appropriate for automatically effecting the engraving of the numerals O to 9 in their normal succession; the groove 16 is shown by a series of thick lines and its deviation from the main helical line is responsible for traverse of the engraving tool in the transverse direction with respect to the numeral to be engraved. As an example of the formation of the cam surface the section in Figure 4 is of the contour suitable for engraving the numeral 2, as engraved also appearing in Figure 4. By way of illustrating the operation of the copy cam, its action in guiding the engraving tool to cut. the numeral 2 will now be followed. In the developed view appearing in figure-3 the cam has been-regarded as divided along a line parallel to theaxis of the cam corresponding to the middle of the idle period, this being. shown as the point A. The corresponding position of the pointer 4 is regarded as the starting position to which, by suitable shaping of the cam surface and deviation of the groove, it is re; turned after the engraving of each numeral.

Between A and B the contour and groove arerespectively so formed as to move the pointer 4% in such a manner as to bring the engraving tool 1 to the corresponding polnt B shown on the representation of the numeral, and at this moment the cam groove 22 functions to cause descent of theengraving tool 1 on to the work-piece 7 Deviation.

of the groove 16 between the points B and C operates to cause the tool 1 to move to.- ward the right having regard to the numeral finally engraved and at the same time the contour of the cam between the same points,

causes the tool to move in the upward direction, the combined action resulting in the engraving of the portion B, C of the-1111; meral. In the next stage from C to D the direction of the groove 16 is unchanged so.

that motion of the tool toward the right is continued, but the direction of inclination of the cam surface with respect to the pointer 4: changes producingmotion of the tool in the downward direction which, as will be seen fromthe reproduction of the numeral in Figure 4, is what is required. Similarly the action of the groove and contour of the cammay be traced inrespect of the remain: ing portions E, F of the numeral and will be obvious without further explanation.

In the machine illustrated in Figures .5

to 8, the copy cam 5 is built up of a series of discs each having a groove for co-operation with the pointer 41. These discs are mounted by means of a feather 30 on a shaft 31 capable of both rotary'and axial movement in bearings32, the caps 33 of which 7 are hinged and secured by screws, as illustrated, to permit of the ready removal and replacement of the shaft 31. It is thus possible to assemble on the shaft discs, the contour of which and the groovesin which rep,-

resent various characters which it is desired.

shall be automatically engraved in a sequence determined by the order of assembly of the discs on the shaft 31. The shaft driven by means of gear wheels 34 of equal size from a shaft on whichmay also be fixed the cam 21, this shaft, therefore, combining thefunctionsof the shafts 13 and 20 in the machine illustrated in Figures 1 and a 2. In order that the shaft 31 may be rothe cam disc next in order into contact with the pointer 4, the latter being'meanwhile lifted clear of the copy cam 5. To effect the former motion there is provided a screwed spindle 37 having a pinion 38 adapted to be engaged by a segmental rack 39 on a disc 40 fitted on the shaft 35. As

indicated, this disc may also carry the segmental bevel rack 29 which is operative to move the work-piece during the idle period.

Engaging the screwed spindle 37 is a sleeve 41 provided with a forked extension 42 adapted to engage behind a flange 43 on the,

end. of theshaft 31.: Thediameter of the pinion 38, the length ofthesegmental rack 39 and the pitch of the screw 37 are such. that on each revolution. ofthe disc 40,

which corresponds to one revolution of the copy cam 5, the sleeve 41 and consequently the shaft 31 are advanced toward the left as seen in Figure 5 through a distance corresponding to the width of one vof the discs constituting the cam 5; the engraving operation corresponding to this cam is then performed, after which, due to reengagement of the pinion 38 and rack 39, the shaft 31 is again advanced by the width of one disc and so on. p r

In order that during axial motion'of the shaft 31 the pointer 4 shall be lifted clear of the cam discs, at pivoted lever 44 is associated with the pointer and by means of a tension spring 45 is maintained in contact with a cam 46 mounted on the shaft 35. The nature ofthe connection between the lever 44 and the pointer 4 is such as freelyv to permit motion of the'latter inthe direction of its length due to the normal opera tion of the cam discs, but, on a projecting portion of the cam 46 coming into contact, with the lever 44, the latter is effective to remove the pointernfrom contact with the;

camf5.- This action istimed to take place immediately-before axial motion of the shaft 31 occurs and the pointer iszonly' restored to its normal position afterthe-next disc in sequence has been brought into the operativeposition. j I I As regards the construction of the copy. cam and the means for'lifting the pointer 4 out of contact with it during a portion'of". each idle period, the construction of ma-- chine depicted in Figures 7 and 8is similar to that described with reference'to Figures:

5'and 6. Means is, however, provided to. enable use to be made of'the various cam discs inany desired order independently of that .inwhich" they are assembled on theshaft 31. For this purpose there is pro vided aselector drum: 47 rotatably mounted with its axis parallel to the shafts 31 and. 35 and provided with a series of rows of holes 48. Three of-such rows only are shown in the drawings and the number of holes in each row corresponds to the maximum number of cam discs which it is possible to mount on the shaft 31. In respect of each rowthere is provided a pin 49 which, as indicated, may be constituted by a screw adapted to be inserted in any one of the holes in that row. On the left-hand end of the'shaft 31 as seen in Figure 7 there is ,rotatably mounted a member 50 havingadownwardly. directed extension 51 adapted to engage with any one of the pins 49; The:

member 50 also extends Jupwardlyto engage in a fork like manner, as indicated. in:Fig-- ure 8, a stationary bar. 52,whereby, although the shaft'3lvrotates, the member51is pre-V vented from doing'so while being capable of partaking in any axial movement of the shaft. The shaft is continuously urged to-,

ward the left as seen in Figure 7 by'means of a weight '53 attached to-a cord 54ar-" ranged to hangover a pulley 55 and attached to the sliding member 50. Motion in this direction of the shaft is,however, limited by:- engagement of the member 50 witlrone of the pins 49 and it will be seen that such motion and, therefore, the particular cam disowhich' is brought to the operative p.osition,i

is determined by the position of the pin-49" in that row of holes in the selector drum which. for the time-being is opposite/the member 50. Motion of the shaft 31 in the opposite direction, that is to say toward the right as seen in Figure 7, is due'to engage ment of a pinion r56,frictionally mounted. on a transverse shaft 57, with a series of--- teeth 58 out completely around the shaft 31 so thatin spite of the rotation of that shaft the pinion 56 and teeth 58 are continually The shaft 57 also carries abevel pinion adaptedto engage a segmental rack 59 on a disc 60 mounted on the shaft 35. The. length and position of thisrack in engagement.

5 ofthe idle period. By this means the-shaft 31 is moved toward the-right as seen in Figure 7 from the position it is occupying by virtue of contact between the member 50 and one of the pins 49. If, asindicated in 10 Figure 7, the pin in operation occupies its extreme left-hand position, the movement of the shaft 31 toward the right will be the maximum that can be imparted by rotation of the shaft 57. If, however, the pin 49 be in any other position a less movement is required and is indeed only possible owing to contact between the member 50 and the lefthand bearing 32. In this case the excess of rotation of the bevel wheel engaging the rack 59 over that actually required is allowed for owingto the fact that the pinion 56 is only frictionally driven'from. the shaft.57. .As soon as the rack'59 has'passed-out'of engagement with its bevel pinion the shaft 31 is again free to be moved axially toward the left under the action of the weight 53, so as to bring a fresh cam disc into operation as determined by movement of the selector drum which is-produced in the following manner:- 7 i a J 1 On the shaft 35 there is'mounted a cam 61 adapted once in each revolution to depress alever'62, pivoted at 63 to a fixed member and carrying at its other end a spring-- pressed pivoted pawl 64 adapted to engage a series'of pins 65 projecting from the side of the selector drum 47. 'Return motion of the lever .62 is due to a spring-pressed plunger 66 bearing on its-under side so that, as soon as thestep onthe cam 61 passes the projection on the lever 62 bearing on the cam-,the lever 62 and its pawl 64 rise and rotate the selector drum 47 through an angle corresponding to the pitch of the rows .of holes 48, reverse motion of the drum 47 being prevented-by a pivoted detent .67 biased by means of a spring plunger 68 and adapted to engage the pins 65 as indicated. This action occurs after the shaft 31 has been returned to the'right as seen in Figure 7 and before it is released to be again moved in the left-hand direction by, the action of the It will be obvious that, instead of ajgroove cut in the cam surface, a raised rib'o'r the like may be employed, the controlling memher being correspondinglymodified to bear on the sides of the: rib, and in the follo'w ing claims refere'ncesto' the-groove and to" the controlling member are to'be understood as including such modified structures. What I claim and desire to secure by Letters Patent of the 'United States is 1. An engraving machine, comprising a copy cam, means forrotating said cam,"said' cam having a contoured portion, said por-- tion having a groove,'-an engraving'tool capable of universal movement in a given plane, and a controlling member capable-of similar movement, said member having operative connection, 011 the one hand with said engraving tool, and on the other hand with said contoured portion, for applyingto said tool a component of motion in a given direction, and with said groove for-applying a second component at right angles thereto. 2. A machine for successively engraving a series of separate characters, comprising in combination an engraving tool capable of'universalmovement in a plane, a con-. trolling member in operative connection; with said tool and capable'of similar movement,a copy cam, means for rotating said cam, a contoured portionofsaid cam adapted to co-operate with said controlling member, a groove in the surface of said cam also adapted to co-operate with said controlling member, means for bringing said engraving tool into contact with the work-piece where.- on a character is to. be engraved during the operative portion of each revolution of said. cam wherein saidcontrolling member CO-z operates with said contoured portion and-- means for separating said tool and. said work-piece during the remainder of each revolution of said cam. Y

3. In an engraving machineias in claim 2, means for moving the work-piece so'as to bring into proximity tolthe engraving tool that portion of said work-piece whereon itis desirednext to engrave a character during said remainder of each revolution of said cam wherein said' tool and said work-piece, are separated. 1

41A machine for successively engraving aseries of separate characters, comprisingin combination an engraving tool capable of universal movement in apla-ne, a controlling member in operative connection with said tool andcapable of similar movement, a copy cam, means for rotating said -cam,-.a contoured portion. of saidcam adapted to co-opera-te with said controlling-member, a groove in the surface of-said cam also'adapted to co-operate withsaid controlling mem-- ber, means for movingsaid controlling v member out of operative relation with saidcamat the end of the operative portion of each revolution of said cam, means for mov-.' ing said cam in an axial direction and means for restoring said controlling member into operative relation with said cam.

5. An engraving machine, as-in claim 1, wherein-said copy camis shaped to provide.

shaft Whereon said a helical surface in which said groove is formed and including a stationary screwed spindle in operative engagement with said cam and whereon said cam is rotatably mounted, the pitch of said screwed spindle being equal to that of said helical cam surface.

6. An engraving machine comprising in combination an engraving tool capable of universal movement in a plane, a controlling member in operative connection with said tool and capable of similar movement, a series of cam discs in operative relation with said controlling member, a guiding groove in the surface of each disc also in operative relation with said controlling member, a shaft whereon said discs may be assembled in any desired order, means for rotating said shaft, means for separating said engraving tool from the work-piece whereon the engraving operation is to be performed during a portion of each revolution of said shaft and means for moving said shaft axially during said period of separation a distance equal to the width of a single disc.

7. An engraving machine comprising in combination an engraving tool capable of universal movement in a plane, a controlling member in operative connection with said tool and capable of similar movement, a series of cam discs in operative relation with said controlling member, a guiding groove in the surface of each disc also in operative relation with said controlling member, a shaft whereon said discs may be assembled in any desired order, means for rotating said shaft, means for separating said engraving tool from the work-piece whereon the engraving operation is to be performed during a portion of each revolution of said shaft, a screwed spindle, means for rotating said spindle during said period of separa tion and a member operatively connecting said spindle with said shaft to produce axial movement of said shaft on rotation of said spindle.

8. An engraving machine comprismg 1n combination an engraving tool capable of universal movement in a plane, a controlling member'in operative connection with said tool and capable of similar movement, a series of cam discs in operative relation with said controlling member, a guiding groove in the surface of each disc also in operative relation with said controlling member, a discs may be assembled in any desired order, means for rotating said shaft, means for sliding said shaft axially whereby any one of said discs may be brought opposite said controlling member and selector mechanism whereby the extent of said axial sliding may be predetermined.

9. An engraving machine comprising in combination an engraving tool capable of universal movement in a plane, a controlling by any oneof said 7 said combination an engraving the: surfaceof means for sliding said shaft axially whereposite said controlling member, a rotatable selector drum in parallel; relationship with said shaft and formed with parallel rows of holes spaced around said drum, a pin in respect of each row and adapted to be inserted in any of said holes in that row and a member carried by said shaft and adapted to cooperate with said pin in said row for the time being in the operative position in proximity to said shaftwhereby the extent of said axial sliding is predetermined.

discs may be broughtop- 10. An engraving machine comprising in combination an engraving tool capable of universal movement 1n a plane, a controlling member in operative connection with said tool and capable of similar movement, a series of cam discs in operative relation with member, a guiding groove in the surface of each disc also in operative relation with said controlling whereon said discs may be assembled in any desired order, means for rotating said shaft, means for sliding said shaft axially in one direction whereby any one of said discs may be brought opposite said controlling member, a rotatable selector drum in parallel relationship with said shaft and formed with parallel rows of holes spaced around said drum, a pin in respect of each row and adapted to be inserted in any of said holes in that row, a member carried by said shaft and adapted to cooperate with said pin in said row for the time being in the operative position in proximity to said shaft whereby the extent of said axial sliding is predetermined and means for returning said shaft to its initial position.

11. An engraving machine comprising in tool capable of universal movement in a plane, a controlling member in operative connection with said tool and capable of similar movement, a series of cam discs in operative relation with member, a shaft adapted to be inserted in any of said holes in that row,

a member carried by said shaft and adapted to co-operate with said pin in said row for the time being in the operative position in the extent 0 proximity to said shaft whereby f said axial sliding is predeterminech'nieans for returning said shaft to its initial position and means for rotating said drum through an angle corresponding to the pitch of said rows after said return of said shaft.

JOHN DUNLOP LINN. 

